Strain relief washer



Feb. 6, 1962 N. R. scHwARTz 3,020,331

STRAIN RELIEF WASHER Filed June 22, 1959 INVENToR. Mfr/eww ff sr//wffz United States Patent Office 3,020,331 Patented Febq 6, 1962 amasar STRAIN RELIEF WASHER Nathan R. Schwartz, Yonkers, N.Y., assigner, by nlesue assignments, to Swivelier Company, Inc., Nanuet, NFI., a corporation of New York Filed June 22, 1959, Ser. No. 821,861

Claims. (Cl. 174--62) The instant invention relates to lighting fixtures in general and more particularly to a novel construction for a strain relief washer which is included as a portion 0f the lighting fixture.

In many types of electrical devices, it is a requirement of the underwriters thaty the energizing conductors for the device must be slack in the region of the device internal terminals. Means, commonly referred to as strain relief means, must be included so that any mechanical force exerted upon the conductors will not break the electrical conductors loose from the terminals within the device.

Accordingly, it is a primary object 'of the instant invention to provide a novel construction for a strain relief means which is readily fabricated of sheetmaterial and which requires an inexpensive manufacturing operation.

Another object is to provide a novel combination element which includes both a strain relief section and a washer section.

These as well as other objects of the instant invention shall become readily apparent after reading the following description of the accompanying drawings in which:

FIGURE l is a fragmentary view, in perspective, of a lighting fixture and a strain relief means constructed in accordance with the instant invention.

FIGURE 2 is a side elevation of a combination washer strain relief means.

FIGURE 3 is a plan view of the combination means of FIGURE 2.

FIGURE 4 is a perspective view of a grommet means which is utilized in combination with the strain relief means.

Briefly, the device of the instant invention comprises a combination element including a washer section and a strain relief section inclined with respect to the washer section. .The washer section includes an opening having a straight portion which cooperates with a flattened surface of a nipple extending from the lighting fixture so that relative rotation is prevented between the combination washer strain relief means and the lighting fixture. The washer section is interposed between a lock washer and a canopy mounting means to which the lighting fixture is secured. The energizing conductors of the lightf ing fixture pass through the hollow nipple and thence through an opening in the strain relief section with a grommet being inserted in this opening to fit snugly against the conductors yet protect the conductors from damage which would be caused by rubbing against the sharp edges which define the opening in the strain relief section. Y

Now referring to the figures, an electrical device taking the formof lighting fixture 11 is secured to a mounting means in the form of dish shaped canopy 12 in a manner to be hereinafter explained. Canopy 12 is adapted to be removably secured to a Wall or ceiling box of the con ventional type (not shown) having energizing conductors entered therein. Apertures 13 and 14 through canopy 12 provide entrances for mounting bolts (not shown) which are engageable with appropriately threaded openings in a bracket or other conventional securing means associated with the 'wall box.

Lighting fixture 11 includes a lamp shade 15 secured to a swivel unit 16. Swivel unit 16 is of a typefwell known to the art such as illustrated in my copending soy application ySerial No. 679,668 filed August 22, 1957, entitled Full Turn Swivel Unit, which is assigned to the assignee of the instant invention. Swivel unit 16 is constructed so that lamp shade 15 may be rotated substantially 360 about the longitudinal axis of base 18 and also for approximately about an axis disposed `perpendicular to this longitudinal axis.

Hollow threaded nipple 17 extends from the base 18 of lighting fixture 11 through a central opening in canopy 12 as well` as through an opening 19 in washer section 2li of combination washer strain relief means 25. Opening 19 is'generally circular in shape but includes a flat portion 21 which cooperates with a flat surface 22 of nipple 17 so as to mount combination means 25 in a manner such that it cannot rotate with respect to lighting fixture 11. Washer section 2t) is positioned adjacent to the inner surface 23 of canopy 12., The toothed lock-washer 24 rests against washer section 20, being interposed between tightening nut 26 and washer section 20 as seen in FiG- URE 2. Washer section 20 is slightly concave when relaxed and thereby provides a spring tensioning action when nut 26 is threaded upon the nipple 17 to draw lock washer 24, washer section 20, canopy 12 and lighting fixture 11 together. f

Combination means 25 further includes a strain relief sec-tion 30 inclined at approximately 45 with respect to washer 'section 20 in the embodiment illustrated. Notches 31, 32 define a portion 33 of reduced area along which the angular inclination of strain relief section 30 may be adjusted'with respect to washer section 20.

Grommet means Si) is disposed within opening 33 of strain relief section Sii. Insulated conductors 41 and 42, which are connected to the internal terminals (not shown) of lighting fixture 11, in a well known manner to the art, extend through hollow nipple 17 with one conductor 41 passing through notch 32 and the other conductor 42 passing through notch 31 and then both conductors 41, 42 passing through the central hole 51 of grommet means 50.

Grommet means Sti is constructed of a resilient substantially rigid plastic material such as nylon and in ciudes yan inclined cam surface 52 which extends from one end 55 of grommet means Sti and terminates in a latch surface 53 which defines one side of annular groove S4. Grommet means 5t) is mounted to strain relief section 3u by inserting end 55 into opening 33. As this is done the cam surface 52 is engaged by the surface dening opening 33 and further inward movement of grom- InetL means 5d causes comfression thereof which is taken up by longitudinal slit 55 therein. When strain relief sec n `tion 3i? is disposed within annular groove 54 the resilient nature of 4the material comprising grommet means 50 causes it to resume the shape illustrated in FIGURE 4 with latch `surface 5S being disposed on one side of strain relief sectiont and groove dening surface 57 being disposed on the other side of strain relief section 30 so that grommet means Sii is self-locked to combination means 25.

Itis to be noted, ythat in the region between the internal terminals of lighting fixture 11 and gromrnet means 50, conductors 41 and l2 are slack to avoid placing mechanical stresses upon the terminal connections. Since the conductors in passing through'nipple 17 and through relief opening 33 are somewhat looped and are snugly fitted within grommet means opening 51, any mechanical force applied to the free ends of conductors 41 and 42 in FIGURE 1 will not act upon the internal terminal connections of lighting fixture 11.

Thus, I have provided a novel combination Washer strain relief means Z5 which is utilized as a portion of the connecting means which secures lighting fixture 11 to its canopy 12 and also serves to relieve the internal ter- 3 minals of lighting fixture il from mechanical stresses which maybe applied to the energizing conductors 4l and 42. of lighting fixture 11.

Although l have here described preferred embodiment of my novel invention, many variations and modifications will now be apparent to those skilled in the art, and I therefore prefer to `be limited, not by the specific disclosure herein, but only by the appended claims.

I claim:

1. In combination a mounting means adapted to be removably connected to a support having electrical power means associated therewith, an electrical device secured to said mounting means, said electrical device including a first and a second electrical conductor insulated from one another and both extending through an opening in said mounting means, a first means including a washer section having an opening aligned with said mounting means opening and having both of said conductors extending therethrough, said first means also including a strain relief section formed integrally with said washer section, both of said conductors extending through hole means in said strain relief section, said strain relief section being inclined ith respect to said washer means; said first means further including a section of reduced area defining a boundary between said strain relief section and said washer section along which the angular disposition between said strain relief section and said washer section may be adjusted; said washer section opening being defined by a formation which cooperates with' a formation of said electrical device to prevent said first means from rotating relative to said electrical device.

2. In combination a mounting means adapted to be removably connected to a Support having electrical power means associated therewith, an electrical device secured to said mounting means, said electrical 'de yice including a first and a second electrical conductor insulated from one another and both extending through an opening in said mounting means, a fust means including a washer section having an opening aligned with said mounting means opening and having both of said conductors extending therethrough, said first means also including a strain relief section formed integrally with said Washer section, both of said conductors extending through hole means in said strain relief section, said electrical device also including a hollow nipple extending through the openings of said mounting means and said washer section, both of said conductors passing through said nipple, the outer circumferential surface of said nipple including a dat portion and said Washer section opening being partially defined by a portion cooperating with said nipple flat portion to prevent relative rotation between said electrical device and said first means.

3. In combination a mounting means adapted to be removably connected to a support having electrical power means associated therewith, an electrical device secured to said mounting means, said electrical device including a first and a second electrical conductor insulated from one another and both extending through an opening in said mounting means, a first means including a washer section having an opening aligned with said mounting means opening and having both of said conductors extending therethrough, said first means also including a strain relief section formed integrally with said washer Section, both of said conductors extending through hole means in said strain relief section, said electrical device also including a hollow nipple extending through the ,openings of said mounting means and said washer section, both of said conductors passing through said nipple, the outer circumferential surface of said nipple including a flat portion and said washer section opening being partially dened by a portion cooperating with said nipple flat portion to prevent relative rotation between said electrical device and said first means, said strain relief section being inclined with respect to said washer means.

4. in combination a mounting means adapted to be removably connected to a support having electrical power means associated therewith, an electrical device secured to said mounting means, said electrical device including a first and a second electrical conductor insulated from one another and both extending through an opening in said mounting means, a first means including a 'washer section having an opening aligned with said mounting means opening and having both of said conductors extending therethrough, said first means also including a strain relief section formed integrally with said washer section, both of said conductors extendingthrough hole means in said strain relief section, said electrical device also including a hollow nipple extending through the openings of said mounting means and said washer section, both of said conductors passing through said nipple, the outer circumferential surface of said nippie including a flat portion and said washer section opening being partially defined by a portion cooperating with said nipple fiat portion to prevent relative rotation between said electrical device and said first means, said strain relief section being inclined with respect to said washer means, said first means further including a section of reduced area defining a boundary between said strain relief section and said washer section along which the angular disposition between said strain relief section and said washer section may be adjusted.

5. In combination a mounting means adapted to be removably connected to a support having electrical power means associated therewith, an electrical device secured to said mounting means, said electrical device including a first and a second electrical conductor insulated from one another and both extending through an opening in said mounting means, a first means including a washer section having an opening aligned with said mounting means opening and having both of said conductors extending therethrough, said first means also including a strain relief section formed integrally with `said washer section, both of said conductors extending through hole means in said strain relief section, said electrical device also including a hollow nipple extending through the openings of said mounting means and said washer section, both of said conductors passing through said nipple, the outer circumferential surface of said nipple including a at portion and said washer section opening being partially defined by a portion cooperating with said nipple flat portion to prevent relative rotation between said electrical device and said first means, said strain relief section being inclined with respect to said washer means, said grommet means comprising a split ring constructed of resilient somewhat rigid material.

References Cited in the file of this patent UNITED STATES PATENTS 1,790,933 Leviton Feb. 3, 193i 2,202,315 Langdon May 28, 1940 2,420,826 Irrgang May 20, 1947 FOREEGN PATENTS 571,189 Great Britain Aug. 10, 1945 

